Drill pipe protector having tapered latch

ABSTRACT

A drill pipe protector adapted to fit in encircling relation about a joint of rotating drill pipe and to prevent the external surfaces of the drill pipe from becoming worn by rubbing against the walls of a bore within which the drill pipe is rotated. The drill pipe protector comprises a generally cylindrical structural element that is hinged to enable the device to be assembled to the drill pipe and includes a body of molded yieldable material that encapsulates the structural element and extends beyond the surfaces of the drill pipe for contact with the wall of the bore within which the drill pipe is rotated. For the purpose of locking the pipe protector device to the drill pipe, the structural element is provided with a pair of tapered flanges defining elongated diverging cam surfaces each having transverse locking depressions. A latch element is provided having opposed tapered diverging tab elements that are adapted to be received in camming engagement with the cam surfaces and are controllable moved toward or away from one another to cause controlled compression of the yieldable material against the drill pipe upon movement of the latch element relative to the tabs. At least one locking projection is carried by the latch element and is received within the locking depressions to lock the latch element in the latching position thereof.

United States Patent [191 Broussard [451 July 15,1975

[ DRILL PIPE PROTECTOR HAVING TAPERED LATCH Dallas N. Broussard, 204Diane St., Houma, La. 70360 [22] Filed: on. 25, 1973v [21] App]. No.:409,428

Related U.S. Application Data [63] Continuation-impart of Ser. No.263,878, June,

19, 1972, abandoned.

[76] lnventor:

Primary E.\'aminer-Charles .l. Myhre Assistant E.ranziner--R. l-l.Lazarus 5 7 ABSTRACT A drill pipe protector adapted to fit in encirclingrelation about a joint of rotating drill pipe and to prevent theexternal surfaces of the drill pipe from becoming worn by rubbingagainst the walls of a bore within which the drill pipe is rotated. Thedrill pipe protector comprises a generally cylindrical structuralelement that is hinged to enable the device to be assembled to the drillpipe and includes a body of molded yieldable material that encapsulatesthe structural element and extends beyond the surfaces of the drill pipefor contact with the wall of the bore within which the drill pipe isrotated. For the purpose of locking the pipe protector device to thedrill pipe, the structural element is provided with a pair of taperedflanges defining elongated diverging cam surfaces each having transverselocking depressions. A latch element is provided having opposed tapereddiverging tab elements that are adapted to be received in cammingengagement with the cam surfaces and are controllable moved toward oraway from one another to cause controlled compression of the yieldablematerial against the drill pipe upon movement of the latch elementrelative to the tabs. At least one locking projection is carried by thelatch element and is received within the locking depressions to lock thelatch element in the latching position thereof.

9 Claims, 6 Drawing Figures DRILL PIPE PROTECTOR HAVING TAPERED LATCHThis is a continuation-in-part of application Ser. No. 263,878, filedJune 19, 1972, and is now abandoned.

FIELD OF THE INVENTION The present invention relates generally to pipeprotector members utilized to prevent wear on the external surfaces ofdrill pipe and more specifically to a pipe protector structure includingnovel latching means for locking the pipe protector in encirclingrelation about a section of drill pipe and controllably compressingyieldable material of the pipe protector to control frictionalengagement of the yieldable material and the drill pipe.

BACKGROUND OF THE INVENTION In the drilling of oil, gas and water wellsby the rotary method, the well bore or hole in the earth surface istypically formed by means of a drill bit which is secured on the end ofwhat is generally termed a drill string. The drill string is formed of aplurality of drill pipe sections that are connected by couplings whichare male and female threaded elements that may be threaded together tosecure the drill pipe section into an integral drill string unit.

As the well bore is progressively deepened by drilling operations,additional pipe sections are added to the drill string at the earthssurface so that the drill bit or cutting tool at the lower end of thedrill string will be maintained in proper engagement with the bottom ofthe well bore until the well bore is drilled to the desired depth.During the drilling operations, the drill string will be rotated andsimultaneously lowered in controlled manner to transmit rotationalmovement to the drill bit at the bottom of the hole and to maintainpredetermined pressure on the drill bit to insure straight and efficientdrilling of the well bore.

The sections of drill pipe are not considered expendable items in thedrilling of wells. The drill pipes may be used over and over to drillother wells and therefore it is desirable to minimize the amount of wearto which the drill pipes may be subjected during drilling.

In drilling deep bore holes in the earth, such as in drilling to reach adeep production formations, the bore holes are typically of such depththat the metal drill string carrying the drill bit will tend to whiplaterally into abrasive engagement with the metal casing lining the borehole or with the wall structure of the bore hole itself. If the drillpipe is allowed to whip against the casing or well bore wall duringdrilling operations, the abrasion resulting will erode the exteriorsurfaces of the drill string to the point that replacement of the drillstring will be necessary within a short period of time.

It is customary to prevent abrasive metal-to-metal engagement betweenthe drill string and the well casing or the wall of the well bore bymeans of a protector device secured about the drill string. Suchprotector devices are variously called drill pipe protectors or wearpreventors. They typically comprise a sleeve or ring that is split onone side for attachment to the drill string. The sleeve may include aninner reinforcing member, usually composed of relatively rigid metal,and inner and outer layers of yieldable material, such as rubber or anyone of a number of commercially available synthetic rubber-likeelastomeric materials. It is typically the practice in the industry tomold the rubber or synthetic rubber material about the rigid reinforcingmember thereby defining a yieldable inner wall of material forengagement with the drill pipe and defining wear preventing surfacesthat extend beyond the outer peripheries of the drill pipe forengagement with the inner wall structure of the well casing or the wallstructure of the formation in which the well bore is being drilled.

It is desirable that pipe protectors, applied to pipes for the purposeof preventing wear, be applied to the pipes in such manner that theprotector device is secured about the pipe structure in sufficientlytight manner that a non-slip relation is developed between the pipeprotector and the pipe. The pipe protector will generally be applied tothe pipe structure with sufficient tightness that the inner layer ofelastomeric rubber-like material will be compressed to an extentcreating necessary frictional engagement with the outer periphery of thepipe and the pipe encircling band of reinforcing material, which mayalso be referred to as a structural element, will be placed in tension.

Drill pipe protector devices are typically secured in frictionalengagement around the pipe sections of the drill string by means of alatching or retaining mechanism. It is customary to employ a separatetool or tensioning device to contract the jaws of the pipe protectordevice about a drill pipe. After the jaws have been properly contracted,a pin, key or other latching device, may be placed in assembly with thejaws to retain the jaws closed and thereby retain the pipe protectordevice in immovable, but releasable assembly with the section of drillpipe.

In view of the facts that latch devices may become separated from a wearpreventer mechanism during operation of the well drilling mechanism andcan cause expensive repair or fishing operations to retrieve the latchdevices from the well, it is desirable that such latch devices beprovided with a positive locking device that prevents inadvertentseparation of the latch devices during use.

In view of the fact that most drill pipe is rather accuratelydimensioned, it is generally necessary that the drill pipe protectors bealso accurately dimensioned to allow the drill pipe protectors to beplaced in proper frictional assembly with the drill pipe. The band-likepipe encircling structural element and the molded elastomeric rubber-lile body of yieldable material must also be quite precisely dimensioned toenable optimum frictional engagement to exist when the pipe protectorsare applied to the drill pipe. Precision manufacture of drill pipeprotectors in this manner obviously increases the cost of production ofthe drill pipe sections and thereby decreases the commercial feasibilitythereof. It is desirable that drill pipe protectors be capable ofproduction by utilization of low cost production methods and yet becapable of proper assembly with sections of drill pipe to establish thedesired degree of frictional engagement.

It is therefore a primary object of the present invention to provide anovel drill pipe protector structure that may be manufactured simply andefficiently to wide manufacturing tolerance levels and yet be capable ofoptimum assembly to drill pipe sections.

It is another object of the present invention to provide a novel drillpipe protector structure incorporating molded elastomeric material thatis capable of cold flowing to an optimum degree upon assembly of thepipe protector to a section of drill pipe.

It is an even further object of the present invention to provide a noveldrill pipe protector incorporating a latching mechanism to maintain thepipe protector in assembly with a section of drill pipe, which latchassembly may be adjusted as desired to control the degree of compressionof elastomeric material in contact with the outer periphery of the drillpipe.

It is also an object of the prevent invention to provide a locking meansfor positively retaining the latch assembly in the latched positionthereof.

Among the several objects of the present invention is noted thecontemplation of a novel drill pipe protector structure incorporating alatch mechanism including an interrelated cam system enabling the drillpipe protector to be secured to the drill pipe in a manner compensatingfor difference in size of the drill protector structure or the drillpipe caused by rather wide manufacturing tolerances allowed duringmanufacture of the pipe protector and drill pipe.

It is an even further object of the present invention to provide a noveldrill pipe protector structure incorporating a hinged structural band orstructural element for easy application of the pipe protector inencircling position about a section of drill pipe and furtherincorporating a latch mechanism enabling the sections of the structuralelement to be drawn together as tightly as necessary to accomplishoptimum frictional engagement between the pipe protector and the drillpipe about which the pipe protector is assembled.

Another object of the present invention contemplates the provision of anovel pipe protector structure that is of simple nature, is reliable inuse and is low in cost.

Other and further objects, advantages and features of the presentinvention will become obvious upon an understanding of the illustrativeembodiment about to be described and various advantages, not referred toherein, will occur to one skilled in the art upon employment of theinvention in practice.

SUMMARY OF THE INVENTION The present invention concerns a pipe protectorstructure comprising a pipe encircling relatively rigid structuralelement comprising two generally semicylindrical sections that arehinged together along one side, thereby allowing the sections to open injaw-like manner, to allow the pipe protector to be applied in encirclingmanner to a drill pipe. Elastomeric material, such as rubber or any oneofa number of commercially available synthetic rubber-like materials, ismolded or otherwise formed in encapsulating relation about the sectionsof the structuralelement and defines a resilient, generally cylindricalinternal portion disposed for engagement with the outer periphery of asection of drill pipe. The body of elastomeric material may define aplurality of longitudinally disposed ribs equally spaced about the bodystructure which ribs extend beyond the pipe structure sufficiently toprevent contact between any part of the drill pipe structure and theinternal wall defined by a well casing or well bore within which thedrill pipe may be rotated.

A connector or latch device is employed to maintain the jaws of the pipeprotector in closed condition when the pipe protector is in assemblywith a section of drill pipe. The latch structure may include a pair oftapered flanges, formed integrally with the structural element, whichflanges are reverse bent from the structural element to define generallyhook-like tab structures and to define diverging tapered cam surfaces. Atapered latch element having an elongated body portion and a pair ofintegral elongated hook-like cam engaging tab portions, disposed indiverging relation, may be received by the opposed tabs of thestructural element for the purpose of locking the tabs as near togetheras is appropriate to establish an optimum frictional engaging relationbetween the pipe protector and the drill pipe. The hook-like tabportions of the latch element may define cam engaging surface means thatare disposed in diverging relation, corresponding to the divergingrelation of the tapered cam surfaces. The cam engaging surfaces allowthe latch element to be positioned in various latching positionsrelative to the tabs of the structural element thereby allowing the tabsto be slightly spaced or to be tightly drawn together as is necessary toestablish proper frictional engagement between the pipe protector andthe drill pipe.

The latch element may be moved relative to the opposed tabs of thestructural sections of the structural element thereby causing theinterrelated cam surfaces and the cam engaging surfaces to causemovement of the extremities of the structural element either toward oneanother or away from one another as is appropriate to adjust the degreeof frictional engagement between the yieldable material of the pipeprotector structure and the drill pipe.

The opposed tabs may be provided with transverse locking depressionsthat receive a locking projection on the latch device to positively lockthe latch device in the latched position thereof and to prevent thelatch device from becoming separated from the pipe protector during use.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which theabove recited advantages and objects of the invention are attained, aswell as others, which will become apparent, can be understood in detail,more particular description of the invention, briefly summarized above,may be had by reference to a specific embodiment thereof which isillustrated in the appended drawings, which drawings form a part of thisspecification. It is to be noted however that the appended drawingsillustrate only a typical embodiment of the invention and therefore arenot to be considered limiting of its scope, for the invention may admitto other equally effective embodiments.

In the drawings:

FIG. 1 is an isometric view of a drill pipe protector constructed inaccordance with the present invention and illustrating in broken linethe relationship of the drill pipe protector and a drill pipe aboutwhich the protector may be disposed in encircling relation.

FIG. 2 is a sectional view in full line taken along line 22 in FIG. 1and showing, in broken line, the open position of the drill pipeprotector for assembly to or removal from a section of drill pipe.

FIG. 3 is an elevational view illustrating the opposed tapered tabs ofthe structural element in full line with the tab latch element removedand illustrating the tab latch element in broken line.

FIG. 4 is an enlarged fragmentary sectional view of the latchingmechanism of FIG. 2 and illustrating the latching mechanism as beingdrawn into tight assembly by the latch element.

FIG. 5 is an-enlarged section view of the latching mechanism of FIGS. 2and 3, illustrating the latching mechanism as being adjusted to allowthe extremities of the structural element to be spaced as necessary tocompensate for manufacturing tolerances and allow proper frictionalassembly of the drill pipe protector to a section of drill pipe.

FIG. 6 is a perspective view of the latch device showing the tapered camengaging tab portions that define internal cam engaging surfaces.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsand first to FIGS. 1 and 2, there is shown a drill pipe protector,generally at 10, constructed in accordance with the present inventionand shown to be secured in place about a portion of a drill pipe 12shown in broken line. The drill pipe protector may include a relativelyrigid structural core or band for the purpose of adding rigidity to thedrill pipe protector structure and to provide sufficient tensilestrength to prevent unnecessary yielding of the protector structurewhile the drill pipe is being rotated in a heavy and corrosive liquidmedium, such as drilling mud. The structural core of the drill pipeprotector may conveniently take the form illustrated particularly inFIG. 2, where a pair of generally semi-cylindrical structural sections14 and 16 are shown to be connected at one side thereof by means of ahinge 18 defined by interrelated hinge elements formed on eachstructural section. A hinge pin 20 may secure the hinged relationshipbetween the structural sections 14 and 16 of the structural element.

It is desirable that the pipe protector structure be provided with abody of yieldable material defining the internal periphery thereof forestablishing frictional wear resistant engagement with the outerperiphery of drill pipe about which the protector may be disposed inencircling relation. It is also desirable that the drill pipe protectorprovide external surface structure that is capable of engaging the wallstructure of the well casing or well bore within which the drill pipemay be rotating to prevent the wall structure of the well bore fromeroding the drill pipe. It is even further desirable that the drill pipeprotector present an external configuration that allows channeling ofdrilling fluid past the drill pipe protector to prevent the drill pipeprotector from interfering with the flow of the circulating drillingfluid as the well is being drilled. To accomplish these features, thepipe protector structure may be provided with bodies 22 and 24 ofelastomeric material such as rubber or any one of a number ofcommercially available suitable rubber-like synthetic materials that areyieldable and have abrasion resistant qualities. The bodies 22 and 24 ofelastomeric material may be molded about the structural sections 14 and16, respectively, to achieve a permanently fixed or bonded encapsulatingrelation between the bodies of resilient material and the structuralelement. If desired, the structural sections may be perforated orotherwise distorted to insure the maintenance of a permanently bondedrelation between the elastomeric material and the structural sections.

The elastomeric material may be molded or otherwise applied to thestructural sections in such manner that inner portions of the materialshown at 26 and 28, respectively, defines opposed generally cylindricalsurfaces 30 and 32 disposed for engagement with opposed cylindricalsurfaces of the drill pipe 12. It is desirable that the drill pipeprotector be installed in assembly with the drill pipe 12 in such mannerthat the inner bands or areas of material 26 and 28 will yield orcoldflow slightly and will, conform to the configuration of the drillpipe and establish an optimum frictional engagement with the drill pipeto prevent the drill pipe protector from slipping as the drill pipe isrotated.

For the purpose of providing external structural elements for contactwith the wall of a well casing or the wall defined by a well bore and toallow for optimum circulation of drilling fluid past the drill pipeprotector. the bodies 22 and 24 of the elastomeric material may beprovided with a plurality of axially disposed ribs such as shown at 34and 36. The ribs may define contact surfaces such as shown at'38 thatextend radially beyond the couplings of the drill pipe. The contactsurfaces 38 will ordinarily be disposed in spaced relation with theinternal wall of the well casing or well bore while the drill string isrotated during drilling operations. If the drill string should whip asit is rotated, the contact surfaces 38 of the ribs 34 and 36 will engagethe wall structure of the well casing or well bore and will therebyprevent the drill pipe from coming into abrasive contact with the wellcasing or well bore. Any wear. therefore, that is allowed to occur, willbe limited solely to the wear resistant ribs 34 and 36 of theelastomeric bodies 22 and 24. If the elastomeric bodies should becomeworn to the point that abrasive contact between the drill pipe and thewall surfaces of the well casing or well bore may occur it will simplybe necessary to replace the wear preventor device at the time the drillstring is removed from the well for repair or replacement of the drillbit or for any other reason. Ordinarily it is not expected thatreplacement of the wear preventors will be necessary during drilling ofa single well.

Thespaced ribs 34 and 36 of the yieldable bodies of elastomeric materialeffectively define a plurality of spaced longitudinal verticallyoriented slots or channels 37 through which the drilling fluid may flowduring the drilling operation. Moreover, the spaced ribs defined by theslots or channels formed in the elastomeric bodies, effectively createagitation of the drilling fluid as it is circulated past each of thewear preventors, thereby enhancing the ability of the drilling fluid toentrain the drilling cuttings that are created by the bit as the well isbeing drilled.

When it is desired to place pipe protectors in assembly with the variouspipe sections of a drill string, it is desirable that the pipeprotectors be longitudinally split to allow the same to be fittedcircumferentially about a pipe section intermediate the couplingsthereof and it is also desirable that the pipe protectors be providedwith a suitable latch mechanism for securing the longitudinally splitportion to prevent inadvertent opening thereof during drillingoperations. One suitable latch mechanism may conveniently take the formillustrated particularly in FIGS. 3 and 4, where the extremities of eachof the structural sections 14 and 16 of the structural element are shownto include portions bent back upon themselves to define a pair ofhook-like tabs 44 and 46. As illustrated in FIG. 3, the hook-like tabs44 and 46 are tapered from a small dimension at the upper extremitythereof to a large dimension at their lower.

extremities and define a pair of diverging cam surfaces 48 and 51. Eachof the cam surfaces 48 and 51 maybe,

without departing from the spirit and scope of the pres ent invention.

As indicated above, it is one of the primary objects of the presentinvention to provide a latching 'mechae nism for drill pipe protectorshaving a facilityfor adjustably latching the wear preventor to thedrillstem in such manner that a particular'degree of compression of theinternal portions 26 and 28; of the elastomericbodies 22 and 24 mayoccur to establish an optimum degree of frictional engagement with thedrillpipe. It is desirable, therefore,-that the latching mechanism becapableof moving the opposed extremities 40 and 42 of the structuralsections '14 and 16 into, abutment as shown.iri,FlG,.4, if desired, formaximum compression of the. internal portions 26 and 28 of theelastomeric bQdlfiSrIIqlS alsodesirable that the extremities 40 and 42be capable of being secured or firmly latched with the extremitiesspaced, as shown in FIG. 5, to the degree necessary to obtain propercompression of the internal portions 26 and 28 of the elastomeric bodiesand thereby achieve. optimum frictional engagement between the wearpreventor and the outer peripheryof the drill pipe. The latchingmechanism therefore is capable of compensating for dimensionaldifferences in the periphery of the drill pipe and dimensionaldifferences of the inner periphery portions 26 and 28 of the elastomericbodies 22 and 24, such as might be caused by manufacturing tolerances.

For the purpose of positively latching the drill pipe protector inassembly with the drill pipe and for controllably compressing theinternal portions 26 and of the elastomeric bodies, atapered latchelement is illustrated generally at 50 in FIG. 6. The latch element 50may be providedwith an elongated body portion 52 having a lifting eye 54defined at the upper portion thereof. Portions of the latch element 50may be bent back upon themselves to define opposed elongated camingtabs56. and 58 that are shown to be of tapered configuration, tapering froma small dimension at the upper extremities thereof to a large dimensionat their lower extremities. The camming tabs 56 and 58 may defineinternal camming surfaces 6.0 and 62, respectively, that. are disposedfor cammingengagement with the cam surfaces 48 and 5l defined on thetabs 44.and 46 of the structural sections 14 and 16.

It should be noted that the camming tabs 56 and 58 of the latch elementinclude free extremities'that'are spaced to define an elongated slot 64.The. latch element 50 is placed in assembly with the tabs 44 and 46 ofthe structural sections 14 and 16 by lowering the latch element 50downwardly over the opposed diverging tabs 44 and 46 causing the innerportions of the tabs to be received through the elongated slot 64.

It will typically be necessary to .utilize a tensioning device or clampthat is applied to contract the drill pipe through appropriate openingsformed in the elastomeric bodies 22 and 24. The tensioning device maytypically be a pair of tongs that are received in the indentationsandare manipulated manually to place the drill {pipe protector intensionaroundf a section of drill pipe When the pipe protector is forciblyapplied in encircling relation about the drill pipe bythe tensioningdevice, the elastomeric material defining the internal portions 26 and28 of'the pipe'protectorwill be deformed and frictional contact betweenthe elastomeric body" and the drill pi e will he developed.Simultaneously, the tongs will bring the extremities mend 42 of thestructural sections 14 and 16 int'ojuxtaposition. The opposed divergingtabs '44 and .46.-will either be slightly spaced, as shown in FIGS, orclosely abutted, as shown in FIG.. 4, depending upon the degree ofdeformation that mustoccur inthe inner portions 2 6" and 2 8 of theelastomeric bodies, to compensate for differences in size due tomanufacturing tolerances and to achievethe degree of frictionalengagement necessary for proper assembly of the drill pipe protector tothe drill pipe. After the tabs 44 and46 have been properly positioned,the latch element 50 may be lowered into proper position, therebybringing the camming tabs 56 and 58'into engagement with tabs 44 and 46,and causing the internal camming surfaces 60 and 62' of thelatchelernent to engage cam surfaces '48 and 51 of the tabs 44 and 46.The tensioning device then may be removed frorn the indentations 66 and68 and the natural spring-like tendency or memory of the' elastomericmaterial to returnto its original undeformed state, will develop radialforces tending to separate the extremities 40 and '42 of structuralsections 14 and 16. These'radial forces will p'lacethe latch in tensionand cause the latch element 50 to maintain its latched engagement withthe opposed diverging tabs 44 and 46. v 5

After assembly of thelatch element 50 in its latched relationship withthe opposed diverging tabs 44 and 46, if it is determined thatadditional compression of the inner portions 26 and 28 of theelastomeric bodies is desirable, a bar or other suitable 'device may beinserted into the lifting eye 54 of the latch element and the bar may bestruck with a hammer or other suitable instrument, thereby driving thelatch element downwardly relative to the tabs 44 and 46. When'thisoccurs the cam surfaces 60 and 62 of the latche'lement, interacting withcam surfaces 60 and 62--of the latch eler nent, interacting with camsurfaces 48 and'51 of the opposed tabs, will cause the' tabs to be movedtoward one another Wheri this occurs, the structural sections 14 and 16of the structural element will be placed in further tension therebyfurther deforming the elastomeric material from which theinner'portions2 6 and 28 are composed and further increasing frictionalengageprotector body about a section of drill pipe and bring theextremitiesof the structural element into juxaposition in order that thelatching mechanism may be se cured. As illustrated in FIGS. 1 and 2, thestructural sections 14 and 16 ofthe structural element of the pipeprotector may include a pair of indentations 66 and 68 that may beengaged by a tensioning device, received ment between the'elastomericmaterial and the outer periphery of the clrill pipe. Likewise,controlled reduction the degree frictionalengagernent.between theelastomeric bodies and the drill pipem'ay be caused by slight controlledupward movement of the latch ele- 'ment relative to the tabs'44 and '46.A .bar may be ihserted through theliftin'g eye 54' and the bar may bestruck from the unde'r side, thereby moving the latch element 50upwardly relative to' the tabs 44 and 46.

-When this occurs, the cam surfaces 6 0 a nd 62 'will' allow tabs 44 and46 to move further apart thereby de- 2 creasing tensioning of thestructural sections 14 and 16 andhsimultaneously decreasing the degreeof compression of the inner portion 26 and 28 of the elastomeric bodiesagainst the peripheral surface of the drill pipe.

The opposed tabs 44 and 46 will be disposed in the fully closed positionthereof, bringing the extremities 40 and 42 of structural sections 14and 16 into abutment, when the latch element is positioned with thecamming tabs 56 and 58 fully engaged with tabs 44 and 46. It will not bepossible for the latch element 50 to move downwardly to a sufficientdegree that it will fall loose from the opposed tabs 46 and 48. Thelatch element, therefore, may be disassembled from the opposed tabs onlyby upward movement of the latch element sufficiently to cause the camsurfaces 60 and 62 to move clear of the opposed tabs.

It is desirable that the latch element be positively se cured or lockedin the operative position to prevent it from jarring loose duringdrilling operations and falling loose in the drill bore. Obviously, aloose latch device can interfere with normal drilling operations and candamage the drilling equipment. Moreover, removal of loose metal objects,such as latches for wear preventers can be extremely time consuming andexpensive.

To prevent the latch 50 from separating from the wear preventerstructure, the opposed tabs 44 and 46 may be provided with opposed slotsor recesses 47 and 49, respectively, that may receive one or moreinternal locking projections 65 that positively lock the latch mechanismrelative to the opposed tabs. The latch 50 may be urged or drivendownwardly until the transverse locking projection 65 is received withinthe recesses. If further tightening of the wear preventer is desired,the latch may be driven further downwardly and the interengaging camsurfaces of the latch and the tabs will cause the tabs to be drawntoward one another, thus achieving further compression of theelastomeric body against the drill pipe.

It is also appropriate that the opposed tabs 44 and 46 be properlydisposed in vertical alignment before the latch element 50 is insertedinto engaging relation with the opposed tabs. To accomplish thisfeature, the extremity 40 of the structural element 14 is provided withupper and lower alignment tabs 70 and 72 that may be received withinalignment indentations 74 and 76 defined by the opposite extremity 42 ofthe structural element 16. As shown in FIG. 3, the guide tabs 70 and 72each include one side 78 and 80 which are formed at an acute angle withrespect to the longitudinal axes of the drill pipe protector body. Theside with the acute angle is received in a corresponding and parallelside defined by indentations 74 and 76 by which the two sides of thelatch mechanism are brought into longitudinal alignment.

The guide tabs illustrated in FIG. 3 are shown to be formed on the sameside of the latching mechanism, but it will be understood that one guidetab may be formed on one side and the opposite guide tab may be formedon the other side in alternative embodiments of the present inventionwithout departing from the spirit or scope thereof. The guide tabs maytake various shapes and forms depending upon the particular applicationthereof.

In view of the foregoing, it is readily apparent that I have provided anovel drill pipe protector device that incorporates a flange-keyconnection structure that readily compensates for variations in size ofdrill pipe or variations in the size of the pipe protector itself, whichvariations may be caused by differences in size due to manufacturingtolerances. The pipe protector device of my invention provides aflange-key connection structure that may be easily assembled in tightlylocked assembly even though tolerance variations of the drill pipe orpipe protector device may exist.

A tapered latch is employed having opposed tapered cam surfaces definedby opposed tapered tabs that cooperate with correspondingly tapered tabsformed on the structural element of the drill pipe protector device andeffectively allows controlled variations in tensioning of the structuralelement and deformation of the elastomeric bodies of the pipe protectorthrough employment of suitable cam surfaces that may be adjusted insimple and efficient manner through the use of simple implements such ashammers and bars. My invention also incorporates a structure that may beeasily positioned about a section of drill pipe because of the jawlikeconfiguration thereof that is made possible through the use of a hingedisposed intermediate the extremities of the structural element. Theunique drill pipe protector of my invention may be placed into tensionedassembly with the structure of a drill pipe section through the use ofany simple commercially available tensioning device, including tongs forurging the free extremities of the pipe protector device intojuxtaposition. The latching element may be inserted into proper assemblywith the opposed tapered tabs of the structural element after thetensioning device has been utilized to place the extremities of thestructural element in the desired assembled position thereof. Thecooperating configuration of the locking projections in the latchelement and the locking recesses in the tapered opposed diverging tabsof the structural sections effectively secures the latching element intoimmovable assembly with the tabs and prevents the latching element fromvibrating free of the pipe protector device during drilling operations.

It is, therefore, seen that my invention is one well adapted to attainall of the objects and advantages hereinabove set forth, together withother advantages, which will become obvious and inherent from adescription of the apparatus itself. It will be understood that certaincombinations and subcombinations are of utility and may be employedwithout reference to other features and subcombinations. This iscontemplated by and is within the scope of the present invention.

As many possible embodiments may be made of this invention withoutdeparting from the spirit or scope thereof, it is to be understood thatall matters hereinabove set forth or shown in the accompanying drawingsare to be interpreted as illustrative and not in any limiting sense.

What is claimed is:

1. A device for preventing external wear on drill pipe caused by erosiverubbing contact between rotating drill pipe and wall structure definingwithin which the drill pipe is rotated, said device comprising:

a structural element adapted to be received in encircling relation aboutthe drill pipe, said structural element being defined by opposedgenerally semicylindrical elements;

hinge means connecting said semicylindrical elements on one sidethereof;

the opposite sides of each of said semicylindrical elements beingreverse bent and defining opposed tabs, said tabs diverging downwardlyand outwardly and defining angularly disposed cam surfaces;

at least one body of yieldable material carried by each of saidsemicylindrical elements and presenting external surface means extendingbeyond the outer peripheral surfaces of the drill pipe to preventcontact between said drill pipe and the wall structure defining saidbore;

removable latch means engaging said opposed tabs and cooperating withsaid opposed tabs to lock said device in encircling assembly with saiddrill pipe with said opposed tabs properly spaced to establish properfrictional engagement between said device and said drill pipe, saidlatch means comprising an elongated tapered body portion having opposedcamming tabs defined thereon, said camming tabs being disposed inangularly oriented spaced relation and engaging said opposed tabs toretain said device in encircling relation with said drill pipe; and

locking means comprising locking recess means and locking projectionmeans, said locking means interengaging to positively lock said latchmeans relative to said opposed tabs.

2. A device for preventing external wear on drill pipe as recited inclaim 1:

the inner portion of said body of yieldable material being deformed uponassembly of said device in encircling relation about said drill pipe;and

said camming tabs being capable of various locked positions relative tothe opposed tabs to achieve controlled spacing of the tabs and therebyachieve controlled deformation of the body of yieldable material by thedrill pipe.

3. A device for preventing external wear on drill pipe caused by erosiverubbing contact between rotating drill pipe and wall structure defininga bore within which the drill pipe is rotated, said device comprising:

a structural element adapted to be received in encircling relation aboutthe drill pipe, said structural element being defined by opposedgenerally semicylindrical elements;

hinge means connecting said semicylindrical elements on one sidethereof;

the opposite sides of each of said semicylindrical elements beingreverse bent and defining opposed tabs, said tabs diverging downwardlyand outwardly and defining angularly disposed cam sur faces;

at least one body of yieldable material carried by each of saidsemicylindrical elements and presenting external surface means extendingbeyond the outer peripheral surfaces of the drill pipe to preventcontact between said drill pipe and the wall structure defining saidbore;

removable latch means engaging said opposed tabs and cooperating withsaid opposed tabs to lock said device in encircling assembly with saiddrill pipe with said opposed tabs properly spaced to establish properfrictional engagement between said device and said drill pipe, saidlatch means comprising an elongated tapered body portion having opposedcamming tabs defined thereon, said camming tabs being disposed inangularly oriented spaced relation and engaging said opposed tabs toretain said device in encircling relation with said drill pipe;

locking recess means being defined in said opposed tabs; and lockingprojection means being formed on said latch means and being receivedwithin said locking recess means to positively lock said latch meansrelative to said opposed tabs.

4. A device for preventing external wear on drill pipe as recited inclaim 3, wherein:

said locking projection means comprises a plurality of lockingprojections, each being selectively received within said locking recessmeans depending upon the adjustment position of said latch meansrelative to said opposed tabs.

5. A device for preventing external wear on drill pipe caused byabrasive contact between rotating drill pipe and structure defining abore within which the drill pipe is rotated, said device comprising:

an annular structural element adapted to be received in encirclingrelation about the drill pipe, said structural element being defined bytwo generally semicylindrical structural sections;

hinge means hingedly connecting said structural sections;

a pair of yieldable bodies of wear resistant material being carried oneby each of said structural sections and cooperating to define aninternal generally cylindrical portion for frictional engagement withsaid drill pipe and an external portion for rubbing engagement with thewall structure defining the bore;

each of said structural sections being reverse bent to define hook-likeopposed tabs each having cam surfaces disposed in downwardly andoutwardly diverging relation;

latch means comprising an elongated tapered body portion having opposedcamming tabs formed thereon, said camming tabs being disposed inangularly oriented spaced relation and having cam engaging surface meansdefined thereon engaging said opposed tabs to lock said device to saiddrill pipe and causing said cam engaging surface means to engage saidcam surfaces and maintain said opposed tabs in controlled spacedrelation and to maintain the internal portion of said bodies incontrolled deformed engagement with said drill pipe; and

locking means comprising locking recess means and locking projectionmeans, said locking means interengaging to positively lock said latchmeans relative to said opposed tabs.

6. A device for preventing external wear on drill pipe as recited inclaim 5:

said opposed tabs being tapered and defining diverging cam surfaces;

said elongated camming tabs being downwardly and outwardly tapered anddefining opposed tapered cam engaging surfaces corresponding to theangular relation of said cam surfaces; and

said cam engaging surfaces of said camming tabs being capable ofestablishing various locked position relationships with said divergingcam surfaces upon assembly of said latch means to said structuralelement to achieve various locked relative positioning of said opposedtabs and thereby achieve controlled compression of said yieldablematerial against said drill pipe.

7. A device for preventing external wear on drill pipe caused byabrasive contact between rotating drill pipe and structure defining abore within which the drill pipe is rotated, said device comprising:

an annular structural element adapted to be received in encirclingrelation about the drill pipe, said structural element being defined bytwo generally semicylindrical structural sections;

hinge means hingedly connecting said structural sections;

a pair of yieldable bodies of wear resistant material being carried oneby each of said structural sections and cooperating to define aninternal generally cylindrical portion for frictional engagement withsaid drill pipe and an external portion for rubbing engagement with thewall structure defining the bore;

each of said structural sections being reverse bent to define opposedtab means each being tapered and defining diverging cam surface means;

latch means comprising an elongated tapered body portion having opposedcamming tabs formed thereon, said camming tabs being disposed inangularly oriented spaced relation and having cam engaging surface meansdefined thereon engaging said opposed tab means to lock said device tosaid drill pipe and causing said cam engaging surface means to engagesaid cam surface means and maintain said tab means in controlled spacedrelation and to maintain the internal portion of said bodies incontrolled deformed engagement with said drill pipe;

locking recess means being formed in said opposed tab means; and

locking projection means being formed on said latch means andinterengaging with said locking recess means to establish lockingrelation therebetween.

8. A device for preventing external wear on drill pipe as recited inclaim 7, wherein said locking projection means comprises:

a plurality of projections being defined on said latch means and beingselectively engageable within said locking recess means depending uponthe relative position of said latch means relative to said opposed tabmeans 9. A device for preventing external wear on drill pipe as recitedin claim 7, wherein said locking recess means comprises:

a pluralityof spaced recesses being defined in each of said opposed tabmeans and being selectively engageable with said locking projections toestablish locking engagement therebetween.

UNITED STATES PATENT OFFICE CERTIFICATE OF' CORRECTION PATENT NO. 3 4 7DATED July 15, 1975 INVENTOR(S) Dallas N. Broussard it is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 8, Lines 47 and 48, delete the following words: "60 and 62 of thelatch element, interacting with cam surfaces" Column 10, line 57, afterthe word "defining" add a bore before the word "within".

Signed and Scalcd this Arrest:

RUTH C. MASON Arresting Officer C. IARSIIALI. DANN ('mnmissirmtrufl'arems and Tmdenurks

1. A device for preventing external wear on drill pipe caused by erosiverubbing contact between rotating drill Pipe and wall structure definingwithin which the drill pipe is rotated, said device comprising: astructural element adapted to be received in encircling relation aboutthe drill pipe, said structural element being defined by opposedgenerally semicylindrical elements; hinge means connecting saidsemicylindrical elements on one side thereof; the opposite sides of eachof said semicylindrical elements being reverse bent and defining opposedtabs, said tabs diverging downwardly and outwardly and definingangularly disposed cam surfaces; at least one body of yieldable materialcarried by each of said semicylindrical elements and presenting externalsurface means extending beyond the outer peripheral surfaces of thedrill pipe to prevent contact between said drill pipe and the wallstructure defining said bore; removable latch means engaging saidopposed tabs and cooperating with said opposed tabs to lock said devicein encircling assembly with said drill pipe with said opposed tabsproperly spaced to establish proper frictional engagement between saiddevice and said drill pipe, said latch means comprising an elongatedtapered body portion having opposed camming tabs defined thereon, saidcamming tabs being disposed in angularly oriented spaced relation andengaging said opposed tabs to retain said device in encircling relationwith said drill pipe; and locking means comprising locking recess meansand locking projection means, said locking means interengaging topositively lock said latch means relative to said opposed tabs.
 2. Adevice for preventing external wear on drill pipe as recited in claim 1:the inner portion of said body of yieldable material being deformed uponassembly of said device in encircling relation about said drill pipe;and said camming tabs being capable of various locked positions relativeto the opposed tabs to achieve controlled spacing of the tabs andthereby achieve controlled deformation of the body of yieldable materialby the drill pipe.
 3. A device for preventing external wear on drillpipe caused by erosive rubbing contact between rotating drill pipe andwall structure defining a bore within which the drill pipe is rotated,said device comprising: a structural element adapted to be received inencircling relation about the drill pipe, said structural element beingdefined by opposed generally semicylindrical elements; hinge meansconnecting said semicylindrical elements on one side thereof; theopposite sides of each of said semicylindrical elements being reversebent and defining opposed tabs, said tabs diverging downwardly andoutwardly and defining angularly disposed cam surfaces; at least onebody of yieldable material carried by each of said semicylindricalelements and presenting external surface means extending beyond theouter peripheral surfaces of the drill pipe to prevent contact betweensaid drill pipe and the wall structure defining said bore; removablelatch means engaging said opposed tabs and cooperating with said opposedtabs to lock said device in encircling assembly with said drill pipewith said opposed tabs properly spaced to establish proper frictionalengagement between said device and said drill pipe, said latch meanscomprising an elongated tapered body portion having opposed camming tabsdefined thereon, said camming tabs being disposed in angularly orientedspaced relation and engaging said opposed tabs to retain said device inencircling relation with said drill pipe; locking recess means beingdefined in said opposed tabs; and locking projection means being formedon said latch means and being received within said locking recess meansto positively lock said latch means relative to said opposed tabs.
 4. Adevice for preventing external wear on drill pipe as recited in claim 3,wherein: said locking projection means comprises a plurality of lockingprojections, each being selectively received within said locking recessmeAns depending upon the adjustment position of said latch meansrelative to said opposed tabs.
 5. A device for preventing external wearon drill pipe caused by abrasive contact between rotating drill pipe andstructure defining a bore within which the drill pipe is rotated, saiddevice comprising: an annular structural element adapted to be receivedin encircling relation about the drill pipe, said structural elementbeing defined by two generally semicylindrical structural sections;hinge means hingedly connecting said structural sections; a pair ofyieldable bodies of wear resistant material being carried one by each ofsaid structural sections and cooperating to define an internal generallycylindrical portion for frictional engagement with said drill pipe andan external portion for rubbing engagement with the wall structuredefining the bore; each of said structural sections being reverse bentto define hook-like opposed tabs each having cam surfaces disposed indownwardly and outwardly diverging relation; latch means comprising anelongated tapered body portion having opposed camming tabs formedthereon, said camming tabs being disposed in angularly oriented spacedrelation and having cam engaging surface means defined thereon engagingsaid opposed tabs to lock said device to said drill pipe and causingsaid cam engaging surface means to engage said cam surfaces and maintainsaid opposed tabs in controlled spaced relation and to maintain theinternal portion of said bodies in controlled deformed engagement withsaid drill pipe; and locking means comprising locking recess means andlocking projection means, said locking means interengaging to positivelylock said latch means relative to said opposed tabs.
 6. A device forpreventing external wear on drill pipe as recited in claim 5: saidopposed tabs being tapered and defining diverging cam surfaces; saidelongated camming tabs being downwardly and outwardly tapered anddefining opposed tapered cam engaging surfaces corresponding to theangular relation of said cam surfaces; and said cam engaging surfaces ofsaid camming tabs being capable of establishing various locked positionrelationships with said diverging cam surfaces upon assembly of saidlatch means to said structural element to achieve various lockedrelative positioning of said opposed tabs and thereby achieve controlledcompression of said yieldable material against said drill pipe.
 7. Adevice for preventing external wear on drill pipe caused by abrasivecontact between rotating drill pipe and structure defining a bore withinwhich the drill pipe is rotated, said device comprising: an annularstructural element adapted to be received in encircling relation aboutthe drill pipe, said structural element being defined by two generallysemicylindrical structural sections; hinge means hingedly connectingsaid structural sections; a pair of yieldable bodies of wear resistantmaterial being carried one by each of said structural sections andcooperating to define an internal generally cylindrical portion forfrictional engagement with said drill pipe and an external portion forrubbing engagement with the wall structure defining the bore; each ofsaid structural sections being reverse bent to define opposed tab meanseach being tapered and defining diverging cam surface means; latch meanscomprising an elongated tapered body portion having opposed camming tabsformed thereon, said camming tabs being disposed in angularly orientedspaced relation and having cam engaging surface means defined thereonengaging said opposed tab means to lock said device to said drill pipeand causing said cam engaging surface means to engage said cam surfacemeans and maintain said tab means in controlled spaced relation and tomaintain the internal portion of said bodies in controlled deformedengagement with said drill pipe; locking recess means being formed insaid opposed tab means; and lOcking projection means being formed onsaid latch means and interengaging with said locking recess means toestablish locking relation therebetween.
 8. A device for preventingexternal wear on drill pipe as recited in claim 7, wherein said lockingprojection means comprises: a plurality of projections being defined onsaid latch means and being selectively engageable within said lockingrecess means depending upon the relative position of said latch meansrelative to said opposed tab means.
 9. A device for preventing externalwear on drill pipe as recited in claim 7, wherein said locking recessmeans comprises: a plurality of spaced recesses being defined in each ofsaid opposed tab means and being selectively engageable with saidlocking projections to establish locking engagement therebetween.